Transmission question.

[DocVijay]

I did a search and couldn't find a definitive answer, so I'm aasking again.

Which line is the return line to the transmission from the radiator. One post said to look at the tranny, and the front line is to the radiator and the rearward line is the return line. My lines exit the radiator one above the other. Neither is forward or rearward. There are also post that say the top line (on the radiator) is the return line and also that the bottom line id the return line.

Which is it. It's a 1999 if that matters. Please advise. Thanks.

 

[B94Sport]

Hmmm.... On my 94, which from the sound of it is quite different from your 99, it was the tub that is closest to the passenger side. They are right next to each other on a '94. I can tell you this much though, I figured it out by starting the truck and driving it a few miles, stopping, and getting underneath it and feeling the tubes. One will be noticably hotter than the other, this is the tube from the tranny to the radiator and the other tube is the tube to the tranny from the radiator... Also, do you want to place a temp sender in the tube? I would suggest using the tube from the tranny to the radiator, since that is a more accurate reading on the temp of that the tranny is operating at. If you place it on the line from the radiator, your tranny could easily be running at 240 degrees, but you will get a reading that says much less.

 

[DocVijay]

I'm installing both.

I'm going to install a cooler in the return line, and a temp sender in the line that goes to the radiator. I've got that part sorted out, I just need to figure out which line is which.

 

[B94Sport]

Sounds like a good idea to me. Then like I did, your best bet is probably to drive the truck a few miles and feel the tubes. Stop and go driving is best, since it brings up the temp the fastest. Drive it around town a few miles and then feel them. That is unless someone else can tell you which is which beforehand.

 

[Robert]

The fluid should go from the transmission to the top of the radiator, the bottom of the radiator then goes back into either the auxillary cooler (if equipped) or the transmission.

 

[espnfreak]

The warmer line is the line coming from the trans, the cooler one is the one going back into the trans